Java I/O流 简单实现

package com.tjove.main;

import java.io.BufferedReader;
import java.io.ByteArrayOutputStream;
import java.io.CharArrayReader;
import java.io.CharArrayWriter;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.nio.Buffer;

public class Demo3 {
    public static void main(String[] args) {
        Demo3 demo3=new Demo3();
        
        demo3.reader1();
        demo3.reader2();
        demo3.reader3();
    }
    
    /**
     * 字符流 Reader--->FileReader
     */
    void reader1(){
        char[] c=null;
        CharArrayWriter charArrayWriter=new CharArrayWriter();
        try {
            FileReader reader=new FileReader("e:/src/aa.txt");
            c=new char[10];
            while ((reader.read(c, 0, c.length))!=-1) {
                charArrayWriter.write(c, 0, c.length);
            }
            ;
        } catch (Exception e) {
            e.printStackTrace();
        }
        System.out.println("FileReader的结果：   "+new String(charArrayWriter.toCharArray()));
        
    }
    
    /**
     * 字节流 InputStream--->FileInputStream
     */
    void reader2(){
        byte[] buffer=null;
        ByteArrayOutputStream byteArrayOutputStream=new ByteArrayOutputStream();
        try {
            FileInputStream reader=new FileInputStream("e:/src/aa.txt");
            buffer=new byte[1024];
            while ((reader.read(buffer, 0, buffer.length)!=-1)) {
                byteArrayOutputStream.write(buffer);
                
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        System.out.println("FileInputStream的结果：   "+new String(byteArrayOutputStream.toByteArray()));
        
    }
    /**
     * 装饰--->BufferedReader
     */
    void reader3(){
        byte[] buffer=null;
        String content=null;
        StringBuffer stringBuffer=null;
        String line=null;
        try {
            FileInputStream fileInputStream=new FileInputStream("e:/src/aa.txt");
            InputStreamReader inputStreamReader=new InputStreamReader(fileInputStream);
            BufferedReader reader=new BufferedReader(inputStreamReader);
            
            stringBuffer=new StringBuffer();
            while ((line=reader.readLine())!=null) {
                stringBuffer.append(line);
                
            }
            
        } catch (Exception e) {
            e.printStackTrace();
        }
        System.out.println("BufferedReader的结果：   "+stringBuffer.toString());
        
    }

}